Radio communication device and corresponding method for setting up a communication

ABSTRACT

The invention concerns a radio communication device comprising a base station installed on a vehicle and at least a mobile station in the possession of a residence subscriber located on a site, and said radio communication device is operated by detecting in the base station when the vehicle reaches a site available time windows then by transmitting into these time windows a signal representing the vehicle identity.

This application is the national phase under 35 U.S.C. § 371 of PCTInternational Application No. PCT/FR99/00473 which has an Internationalfiling date of Mar. 3, 1999, which designated the United States ofAmerica.

The present invention concerns a radio communication device and thecorresponding process for establishing a communication.

The invention is applied more particularly although not exclusively toestablishing a communication between the crew members of an aircraft andthe ground staff of an airport where the aircraft is touching down.

It is known that, when an aircraft arrives on a site, it is necessaryfor the members of the crew to restore a link to the ground staff. Thefirst communication to be established is that which provides a linkbetween the pilot and the runway staff responsible for directing theaircraft to its parking position. The radio frequencies which areusually employed for communication with the control tower generallybeing close to saturation, it is not possible to envisage using thosefrequencies for communication with the ground staff.

In the absence of suitable means for a radio communication, thecommunication between the pilot and the runway staff is thereforeimplemented visually by gestures. Irrespective of the difficulties thatsuch a communication can involve under certain meteorological conditionswhen visibility is poor, it is necessary for the runway staff to be inthe field of vision of the pilot, which in itself is a very majoroperational constraint.

When the aircraft has reached its parking position, it is known toestablish a communication between the runway staff and the aircraft crewby connecting an external communication circuit to the internalcommunication circuit of the aircraft. That link is made by means of awire and also constitutes a serious constraint which affects the freedomof movement of the ground staff.

In order to remedy those disadvantages, as disclosed in particular indocument WO 94/28684, it has been envisaged that communications can beestablished between the crew members of an aircraft and the ground staffby using the existing radio communication networks which make itpossible in particular to establish a communication between itinerantsubscribers which are the crew members of the aircraft and residentsubscribers which are the members of the ground staff of an airport, inparticular the runway staff. However, by virtue of the itinerantsubscribers being related to a site of origin, the cost of suchcommunications is high so that this communication system is not theoptimum one.

Taking into account the apparent mobility of the itinerant subscribersand the apparent immobility of the resident subscribers, considerationhas also been given to locally creating a radio communication systemcomprising a base station carried by a resident subscriber andconsidering the aircraft as mobile stations provisionally associatedwith the base station in accordance with the link which is usuallyimplemented in a conventional radio communication system between amobile station and a base station. However it was found that a structureof this type was not suited to setting up a communication of a number ofrunway staff members with the same aircraft, which however it isdesirable to be able to implement.

In accordance with the invention there is proposed a radio communicationsystem between at least one itinerant subscriber installed in a vehicleirrespective of the type of such vehicle (aircraft but also train, boator ship, truck . . . ) and at least one resident subscriber installed ona site, the radio communication system comprising a base stationinstalled on the vehicle and directly associated to at least one mobilestation possessed by a resident subscriber on the site.

Thus, by a reversal of the usual structure of the system, a centralfunction, in relation to the communications envisaged, is given to theaircraft or more generally to the vehicle carrying the base station,which makes it possible in particular by a procedure for uniqueidentification of the base station to produce a relationship between aplurality of itinerant subscribers with the resident subscribers whenthe aircraft arrives on a site.

In accordance with another aspect of the invention it concerns a processfor establishing a communication between at least one itinerantsubscriber in a vehicle and at least one resident subscriber on a site,by means of a radio communication system comprising a base stationinstalled on the vehicle and at least one mobile station possessed by aresident subscriber, said process comprising the steps of detecting inthe base station upon the arrival of the vehicle on a site availabletime windows and emitting in said time windows a signal representativeof an identity of the vehicle in order to make itself directly known tothe mobile stations present on the site. Thus, by ensuring thatidentification of the vehicle is effected in an available time window,it is possible for all the resident subscribers listening in within asuitable range to detect the arrival of the vehicle, in which respectthe different vehicles on the site can thus be detected and identified.

To carry the process into effect, the identity of the vehicle givingrise to the emission of a signal can be a permanent identity(registration or record number of the vehicle) or a provisional identitywhich is representative of the transport operation (flight number ormanifest number . . . ) or an association of those types of identity.

In accordance with a further advantageous aspect of the invention theprocess comprises the step of exchanging the directory data between thebase station and at least one mobile station. The term directory data isused to denote not only the name of the subscribers but also other itemsof useful information for the establishment of communications such aslink organisations or the functions of the subscribers. The residentsubscribers and the itinerant subscribers are thus respectively informedof the local call numbers and identifications of the personscommunicating therewith, in such a way that communications can be easilyestablished between the itinerant subscribers and the residentsubscribers.

Other features and advantages of the invention will be further apparentfrom the following description of a particular embodiment of the deviceaccording to the invention and a particular manner of carrying out theprocess according to the invention, with reference to the accompanyingsingle FIGURE which is a diagrammatic representation of the radiocommunication device according to the invention.

Referring to the FIGURE, the radio communication device according to theinvention is described in relation to itinerant subscribers 1 who aremembers of the crew of an aircraft 2 and resident subscribers 3 who aremembers of the ground crew or staff of an airport site on which theaircraft touches down.

In accordance with the invention the aircraft 2 is equipped with a basestation 4 of a radio communication system while the members of theground staff 3 possess a mobile station 5 adapted to communicate withthe base station 4. The members of the crew 1 of the aircraft 2 can beconnected to the base station 4 either by a wired connection or by awireless connection.

In order to be able to establish communications with the residentsubscribers, it is necessary for the base station to make itself knownthereto. For that purpose, as in a conventional radio communicationsystem, the base station emits a beacon signal which permits the mobilestations to identify it. Preferably the identification of the basestation in the beacon signal includes the aircraft identification and/orthe flight number possibly in compressed form in the case where thenumber of bits available within the beacon signal is not sufficient topermit the inclusion as such of the full identity of the aircraft.Identification of the base station thus permits simultaneousidentification of the aircraft or the corresponding flight number.

In conventional manner, the radio communication system according to theinvention operates in a time division mode on one or more frequenciesand for that purpose comprises a frame having time windows allocated inan organised fashion to the mobile stations and to the base station forthe emission of the communication signals. So that the arrival of afresh aircraft can be perceived by resident subscribers who are eachlistening for at least one beacon signal emitted by the base station ofan aircraft which is already present on the site, provision is made todetect in the base station of an aircraft arriving on said site the timewindows which are already occupied by the base stations of aircraftalready present and to emit the beacon signal representative of theidentity of the arriving aircraft, preferably in a time window which isnot simultaneous with those already used for the aircraft which arealready present, at a frequency which can be used by the base station.It is thus possible for a resident subscriber to be in relationshipsimultaneously with a plurality of base stations and therefore toreceive calls from any one of said base stations or to transmit callstowards one of them.

When the arrival of a base station is detected by a mobile station, thecorresponding resident subscriber has the option of connecting himselfand it is possible to provide different modes of implementation formaking that connection. In accordance with a first mode ofimplementation which is reserved essentially for the runway staff,provision is made for using the registration of the aircraft, whether itcan be read as it appears in large letters on the fuselage of theaircraft as illustrated by the box 6 in the FIGURE, or whether it isknown a priori by the runway staff. In that case it is provided thatacquisition of the identification signs by a resident subscriber on themobile station which he holds automatically communicates him with thepilot of the aircraft. So that a team leader of the runway crew can alsobe involved in the conversation, provision can be made for automaticconferencing when a plurality of mobile stations are communicated withthe same itinerant subscriber.

In accordance with a second implementation of the process, which canalso be combined with the first implementation, detection of the arrivalof a base station on a site by a resident subscriber automaticallycauses the emission towards said base station of directory data inrespect of the resident subscribers, identified as RES1 through RES3 inthe FIGURE, and the return emission towards at least one residentsubscriber of directory data relating to the itinerant subscribers,identified as ITI1 through ITI3 in the FIGURE. The directory datacomprise preferably not only the name and the call number of thedifferent subscribers but also their function and the organisation towhich they are linked. It is then possible for a subscriber to consultthe dedicated directory which is obtained in that way and to call thecommunicating party of his choice.

In order to permit evolution of the situation, identification of theaircraft which are present on the site is preferably effectedperiodically so that mobile stations which were not initially in thezone for reception of the signals of a base station can subsequentlyconnect thereto.

It will be appreciated that the invention is not limited to theembodiments described and variations may be made therein without therebydeparting from the scope of the invention as defined by the claims.

In particular the aircraft belonging to the same airline being generallyhandled by a team of ground operatives who are employees of the company,it is possible to provide certain dedicated functions which areautomatically carried into effect when an aircraft of that airlinearrives on a site.

Although the invention has been described in relation to a systemcomprising a base station which is permanently fitted in each aircraft,it is possible to provide for implementation of the process of theinvention by provisionally fitting a base station to an aircraft afterits arrival on the site and removing it just before the aircraft leaves.

What is claimed is:
 1. A method for establishing a communication betweenat least one itinerant subscriber (1) in a vehicle (2) and at least oneresident subscriber (3) on a site, said method comprising the step ofproviding the vehicle with a radio communication base station (4)emitting a beacon signal including an identification of said vehicle forbeing perceived by at least one mobile station (5) possessed by aresident subscriber (3) and for establishing in said at least at onemobile station (5) a communication with said base station (4).
 2. Themethod for establishing a communication as set forth in claim 1, furthercomprising the steps of detecting in the base station (4), upon thearrival of the vehicle (2) on a site, available time windows andemitting in said time windows a signal representative of an identity ofthe vehicle (2) in order to make itself known to the mobile stations (5)present on the site.
 3. The method for establishing a communication asset forth in claim 1, further comprising the step of exchangingdirectory data between the base station (4) and at least one mobilestation (5).
 4. The method for establishing a communication as set forthin claim 1, wherein the mobile stations (5) perceive several beaconsignals emitted by various base stations (4), and the method furthercomprises the step of selecting a mobile station (5) at least one basestation (4) with which a connection is established.
 5. The method forestablishing a communication as set forth in claim 1, further comprisingthe step of providing automatic conferencing of several mobile stations(5) in communication with an itinerant subscriber.